It is generally recognized that there is a need to separate immiscible liquids. This need is particularly acute with respect to various environmental accidents. Hazardous liquids frequently become mixed with water normally found in the environment. Oil spills are, unfortunately, an increasingly common occurrence which require the separation of the oil so that it may be eliminated as a hazard to the environment.
A wide variety of methods and apparatus have heretofore been proposed to provide an efficient means for removing oil or other liquid contaminants from water, but have been met with little success. Recent methods of dealing with the problem of oil pollution include chemical dispersant, as well as various other methods for separating the oil from the water. For instance, U.S. Pat. No. 4,108,773 of Macaluso issued Aug. 22, 1978, teaches an oil salvaging apparatus comprising a chamber into the base of which contaminated seawater is charged for separation of the liquids of differing densities. The Macaluso reference like many others, however, suffers from significant shortcomings inherently associated with its design, namely, it cannot guarantee the purity of both fluids to be separated because of its inability to regulate injection and evacuation rates.
In Macaluso, water is evacuated from the chamber by means of a pump. The escape velocity of water, therefore, will exceed the buoyancy force of the oil in mixture with the water, preventing the oil's assent to the top of the chamber and instead, being discharged along with the water. Similarly, because the Macaluso reference provides no means for effectively regulating the contaminated water's injection rate, and because the chamber will only support a predetermined weight of water under vacuum, excessive injection rates will result in the discharge of unseparated oil and water either through the chamber's top oil evacuation conduit or out of its lower submerged end.
In general, the prior art methods of separating immiscible liquids fail to take advantage of related fundamental fluid dynamics and separation principles and, therefore, are unable to achieve superior separation rates which are both measurable and predictable. Furthermore, and as exemplified above, prior art methods of separation are often incapable of assuring qualitatively acceptable end-products.
Other methods involve the use of skimmers, surface guides and the like to channel the surface oil to a location where it can be removed by pumps. However, such water is usually removed with the oil.
In many cases, the oil layer is very thin, making it particularly difficult to remove without also removing water. In order to remove small amounts of oil, large amounts of water must also be removed.
The subject invention completely obviates all of the shortcomings associated with the prior art by providing an apparatus and method for continuously separating oil from water at superior rates and purities.